聚酯催化缩聚与热降解过程的半经验量子化学研究
Study on the Mechanism of Catalyzed Polycondensation and Degradation of Polyester with Semiempirical PM3 Method
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摘要: 以苯甲酸β-羟乙酯(BAHET)为模型反应物，采用半经验量子化学方法(PM3)，分析了生成聚酯的催化缩聚与热降解机理。计算结果表明，端羟基氧与酯羰基氧是反应物与金属催化剂作用的活性位。金属催化剂与两者作用后，可以使酯羰基碳的正电性与端羟基氧的负电性增加。由于静电作用力增加，促使缩聚反应得以进行。研究结果表明，在钛系催化体系中，端羟基氧和酯醚键氧能与钛原子作用形成热力学稳定的五元环结构，它的存在将影响钛系催化体系中聚酯的热降解行为。Abstract: Semiempirical method PM3 was firstly applied to study the mechanism of polycondensation and thermal degradation of polyester. During the calculation, benzole acid 2-hydroxy-ethyl ester (BAHET) was used as amodel compound. The results indicate that metal i
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